I have a bucket with a big ram quota on Couchbase 2.5.1.
And give a different workload to it (set/delete/get)
In monitoring I see that “active doc resident” parameter is not 100% and as result the cache miss ratio is about 40%.
Why it is happened? There is a lot of free memory in bucket (it is about 10Gb for low water mark) and I suggest that
active doc resident parameter has to be 100% and cache miss ratio has to be 0
What is the Per Node Ram Quota for the bucket? Are you using “Full” or “Value” eviction in the bucket?
@tgreenstein, Per Node Ram Quota is about 52,7 Gb (Claster Quota is 105Gb)
Bucket quota is 58,5 Gb (it is on 2 nodes).
What do you mean saying “Full” or “Value” eviction in the bucket?
This document explains in a bit more detail the ejection strategi used by CB and how to configure/tune it:
"Ejection and working set management"
I hope this helps
Did we have a fix/solution for the above question.
We are facing the same issue.
We have 8 server nodes with 7 buckets in each.
For one of the bucket, the cache miss ratios is 65% and active docs resident is 7%.
Per Node RAM Quota: 32000 MB
Total bucket size = 256000 MB (32000 MB x 8 nodes)
Cache Metadata: Value Ejection
Could someone kindly check on the same.